Fluke Essential Calibration and Performance Insights for 5450A Portable Multimedia Player

8842A

Instruction Manual

The A/D Calibration procedure is an iterative process. Each pass through the procedure uses the constants stored previously and improves them. Normally, one pass is adequate. However, if the calibration memory has been erased or replaced, or the A/D Converter has undergone repair, the A/D Calibration procedure must be performed twice.

Because the A/D Calibration procedure is iterative, the instrument’s performance can be slightly enhanced by going through the procedure more than twice. However, this is not necessary to meet the published specifications.

6-13. OFFSET AND GAIN CALIBRATION

This procedure calibrates the instrument’s offsets and gains by applying a high and low input for every range of each function. To save time, the 8842A uses each input for as many ranges as possible.

A function is calibrated by pressing the corresponding function button. Once a function is selected, the 8842A automatically steps through each range of that function, prompting you for the necessary reference sources. (The prompts are shown in Table 6-10.) The 8842A does not automatically select another function after one function has been completely calibrated; therefore, the functions may be calibrated in any order.

To perform Offset and Gain Calibration, proceed as follows:

STEP

Table 6-10. Offset and Gain Calibration Steps

DISPLAYED PROMPT

VDC VAC1

2 WIRE kΩ

4 WIRE kΩ

mA DC mA AC1

A B C D E F G

+00.0 mV DC (short)

+19.0 mV DC

+190.0 mV DC

+1.900 V DC

+19.00 V DC

+190.0 V DC

+1000. V DC

10.0mV AC

--

100.0 mV AC

1.000 V AC

10.00V AC

100.0V AC 500. V AC

0.00Ω (short)

10.0Ω (4 wire)

100.0Ω

1.000 kΩ

10.00 kΩ

100.0 kΩ

1000. kΩ

00.0 mA DC (open)	100 mA AC
100 mA DC
	--
1000. mA DC	1000.0 mA AC

Steps D-H not applicable for these

functions.

H

Step H not applicable for these

functions.

10.00 MΩ

1Inputs should be at 1 kHz +/-10%. Performance may be enhanced for specific frequencies (see text).

1.Ensure the A/D Calibration procedure has been completed.

2.Select the desired function by pressing the corresponding function button. The 8842A will display the first prompt for that function.

3.Each time the 8842A prompts you for a reference source, apply this source to the appropriate terminals, and press the STORE button. When STORE is pressed, the numeric display field blanks while the 8842A performs the necessary calculations. (Do not change the reference source while the display is blank.) The 8842A then displays the next prompt. For reference, all prompts are shown in Table 6-10.

6-14